Peek into CORE's design process

Explore 600 Mass
Explore 600 Mass


Mass Ave View
Hover over a hotspot for design features.

Entrance Design

The entrance design incorporates a visible body of slow moving water that runs under the walkway along the side of the building. The bridge is intended to help visitors transfer from a busy urban experience into a quiet, serene environment. The entrance also evokes the Chinese tradition of using bridges or gates to access important places.

“Folding” Glass Corner

A departure from traditional Washingtonian architecture, the articulated “folding” glass of the building’s corner, across from the Chinatown Park on 6th Street, introduces a new formal language to the site. The design takes advantage of the site’s complex geometry to create a prominent corner element with views east down Massachusetts Avenue towards the Capitol.

Mass Ave Elevation

Metal detailing becomes the predominant driver of the Mass Ave elevation. Taking an unorthodox design approach, the U-shaped channel climbs up from the ground to the top of the building, wrapping the stone and then the glass, until it transforms to an open trellis at the top of the building.

Mass Ave Entry Vestibule

Designed with a minimal amount of oversized glass panels, the Mass Ave entry vestibule creates a seamless and clear transition between the outside and the inside. A formal stone panel (Jerusalem Limestone) sits behind the concierge, wrapping under the desk to define and soften this zone in the midst of the granite wall and floor.

Elevator Glass Wall

The glass wall enclosing the elevator consists of 3 layers of glass panels, including different variations of etched film and mirror glass. This allows the glass’ characteristics to visually transform, appearing more solid and metallic during daytime and then as a translucent glowing box in the evening.

Mass Ave Tower

This lantern-like tower serves as the main lobby to the tenant spaces on the 9th and 10th floors, and as the main entrance designator on Massachusetts Avenue. The required 90’-0” setback point at 600 Mass is positioned well above the 9th floor terrace, thereby avoiding the “wedding cake” appearance commonly seen with other buildings.

Rooftop Terrace

Open throughout the day, the 11th floor rooftop terrace is accessible to all tenants in the building and can be used as an event space in the evening. The landscaping is designed with water-efficient technologies, including the ability to capture and reuse 100% of rainwater, minimize water use in the building, and substantially reduce water discharge from the building.

Pastoral Streetscape

Following the Mount Vernon Streetscape requirements, the building landscape is intended to reflect a “walk through” park. As pedestrians approach the building on 600 Mass through the double row of trees, the sidewalk becomes more pastoral and creates a beautiful setting for the retail tenant’s outdoor seating on a high-traffic avenue.

Alley Configuration

The building site was originally composed of two very different site conditions: a large parcel zone for grand commercial office building developments in the north and a cluster of smaller parcel zones for small- scale developments in the south. A series of complex alley closings were orchestrated to create a viable development and maintain service to all neighboring buildings.

through lobby of 600 Mass

Main Entrance Glass Bridge

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Rooftop Terrace Landscaping and Trellis

The building's white roof is one of the key features that earned 600 Massachusetts Ave its LEED Platinum status while staying within budget. The roof's reflective surface serves as an energy-efficient way to cool the building — saving operational costs over time and decreasing environmental impact.

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The tree-lined entrances and green rooftop terraces of 600 Massachusetts Ave blur the line between indoors and outdoors. Many of the building's lush greenery and natural elements (stone, granite, and water) can be experienced by employees, visitors, and pedestrians, alike.


Eye Street View
Hover over a hotspot for design features.

"Grand Boulevard"

The "two-faced" building has an imposing appearance along Massachusetts Avenue in the tradition of the “Grand Boulevard”, while also honoring the historic setting of Eye Street. Starting as an 11-story glass office tower facing Mass Avenue, the building cascades down towards Eye Street in a series of landscaped terraces atop a brick façade, complimenting the adjacent historic townhouse structures.

Custom Cornice

Inspired by traditional Chinese architectural joinery, a series of custom metal brackets support fritted glass panels. These brackets serve as a cornice — or ornamental molding — for the lower of the two brick façades fronting Eye Street.

Multiple Terrace Levels

The multiple terrace level design along Eye Street is the result of transitioning between neighboring brick façades that are 8 and 3 stories high. The terrace design was conceived to also offer multiple building tenants their own private terrace amenity. All terraces maintain the same specifications as the 11th floor public terrace.

Fritted Laminated Glass Sunshades

The long series of fritted laminated glass sunshades, seen in normal sunlight conditions as a white panel, are designed to shield 80% of all direct heat gain while maintaining soft daylight filtering through the interior office space.

Chinese Elements

Subtle Chinese elements abound on the Eye Street façade, including custom air intake grilles that evoke decorative Chinese symbols (囍), large orange light fixtures inspired by lanterns of the Mid Autumn Festival (中秋節), and two medallions that read “life lasts forever and never ends” in pre-modern day Chinese Characters (長生無極).

Ground Floor Corridor

The ground floor corridor acts as a beautiful and secure thru-lobby, connecting the two street-level access points on Mass Ave and Eye Street. A shuttle elevator is located in its mid-section and provides access to the ground floor, concourse level, and 3 garage levels.

Multi-Use Conference Room

The multi-use conference area is open to all tenants in the building, as well as Chinatown community gatherings. Clever operable panel design creates flexible space that can be reconfigured from a standard meeting room for 30 people, to a training center for 40, or even an auditorium style gathering for 100.

Fitness Center

The fitness center far exceeds typical office amenities, providing tenants with a luxurious club-style environment. Based on a “T” shaped plan, the spa-like reception leads to the workout area, which features rhythmic architectural lighting inspired by the notion of cadence in a workout routine.

Enhanced Historical Context

A pair of 12’-0” wide, 3-story townhouses built in 1852 were originally located mid-block on Eye Street. As part of the construction, they were moved 100’-0” east to abut a neighboring cluster of lower scale townhouses, creating a more meaningful streetscape and enhancing the rich historical context of Eye Street. View a video of the townhouse move here.

How We Do It


At our CORE, we believe the design process begins with exploration.

The 600 Massachusetts Ave journey began by exploring the separate, distinct building requirements that govern high-rise Massachusetts Avenue and historic I Street. CORE worked with Gould Property Company and Oxford Properties Group to develop a timeless design that unifies two vastly different sides of the building.


At our CORE, we believe our best work comes from designing with you.

Environmental responsibility and building longevity are critically important to our clients, Gould Property Company and Oxford Properties Group. We helped them achieve their goal of designing a 400,000 square foot LEED Platinum office building.


At our CORE, we believe intentional design has the power to shape experiences.

From the onset of this project, CORE committed to thinking globally by designing a multicultural, environmentally responsible building. Together with our clients, CORE carefully shaped a desirable, sustainable work space that excites, intrigues, and inspires.


At our CORE, we believe in earning your trust by leading with experience.

Creating 600 Massachusetts Ave involved troubleshooting a unique set of challenges. At CORE, we leveraged the diversity of our team’s skills and experience to realize our clients' vision.

Project Quick View

400,000 SF
Class-A Office Building
Ground Floor Retail
Underground Parking
3 Levels
Rooftop Terrace
5 Levels
HPRB Approval Process
DC Downtown Historical District
Historical Chinatown
Mount Vernon Triangle Overlay
Alley Closing
Special Merit Major's Agent
LEED Platinum
Project Features
  • Class-A Office Building
  • Ground Floor Retail
  • Underground Parking, 3 Levels
  • Rooftop Terrace HPRB Approval Process
  • HPRB Approval Process
  • DC Downtown Historic District
  • Historical Chinatown Mount Vernon Triangle Overlay
  • Alley Closing
  • Special Merit – Mayor’s Agent
  • LEED Platinum

600 Massachusetts Avenue NW is located in the Chinatown neighborhood of Washington, DC. The 11-story office building offers 400,000 SF of multi-tenant space and 20,000 SF of retail space as well as 300 units of underground parking. The design combines highly efficient floor planning, clean aesthetics, luxurious amenities, and green spaces that blur the line between indoors and outdoors. CORE served as Design Architect and Architect of Record for the base building, as well as the lobby and amenity spaces.

Client Owner/Developer

Gould Property Company
Oxford Properties Group


Guy Martin, AIADesign Principal
Rod Sellers, Associate AIAProject Manager
Dean Hutchison JOB CAPTAIN
Michael Borissow DESIGNER

Smriti Nayak Project Architect
Christopher Peli DESIGNER


Clark Construction Group General contractor
SK&A Structural EngineersStructural Engineer
Girard EngineeringMEP Engineer
Wiles MenschCivil Engineer

Gustafson Guthrie NicholLANDSCAPE ARCHITECT

Sustainable Design ConsultingLEED Consultant
Rosa D. Cheney, AIASpecifications
John A. Van Duesen & Associates

AON Fire Protection Engineering


may 16, 2017

How Two Of DC's Recent Law Firm Movers Are Adapting To Their New Offices

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april 27, 2017

Best Real Estate Deals: 600 Mass

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July 15, 2016

Haworth Signs 13,154 SF Lease at 600 Massachusetts Avenue

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april 26, 2016

Inside 600 Mass, a Gould project 30-plus years in the making

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July 30, 2015

Farmers Restaurant Group Signs 12,000 SF Lease at 600 Massachusetts Avenue

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July 30, 2015

Construction Cranes Dance Over D.C. for Capital Fringe

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July 29, 2015

600 Mass Construction July 2015

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June 25, 2015

House Move At 600 Mass Ave

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june 18, 2015

Groundbreaking at 600 Mass Ave

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june 18, 2015

Venable Announces DC 2017 Move to 600 Mass Ave

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CORE architecture + design, inc.
1010 Wisconsin Ave. NW
Suite 405
Washington, DC 20007

t 202.466.6116
f 202.466.6235

For media inquiries, please contact: Samantha Edwards, 571-338-4723, .